Airfield Lighting Device

ABSTRACT

An airfield lighting device, comprising: at least one first light-emitting diode (LED) on a first base body; a first thermally conductive tube with a heat transmission medium; a first heat sink; and a housing, in which the first base body and the first thermally conductive tube are arranged. The first thermally conductive tube is thermally coupled to the first base body and to the first heat sink. The heat transmission medium can circulate in the first thermally conductive tube, such that heat which is produced by the at least one first LED during operation can be dissipated from the first base body to the first heat sink.

An airfield lighting device is specified, having at least onelight-emitting diode according to the precharacterizing clause of claim1.

For aircraft take-offs and landings for example when it is dark and infog, runways have so-called airfield lighting which, for example, canmark the side boundary, the center, the start and the end of the runwaysand taxiways, as well as individual sections. In this case, suchlighting must comply with the official regulations and should be highlyreliable with a long life.

At least one object of specific embodiments of the present invention isto specify an airfield lighting device having at least onelight-emitting diode.

This object is achieved by a subject matter having the features ofindependent patent claim 1. Advantageous embodiments and developments ofthe subject matter are characterized in the dependent claims and willalso become evident from the following description and from thedrawings.

According to one embodiment, an airfield lighting device has, inparticular:

-   -   at least one first light-emitting diode (LED) on a first base        body,    -   a first thermally conductive tube with a heat transmission        medium,    -   a first heat sink, and    -   a housing, in which the first base body and the first thermally        conductive tube are arranged,        wherein    -   the first thermally conductive tube is thermally coupled to the        first base body and to the first heat sink, and    -   the heat transmission medium can circulate in the first        thermally conductive tube, such that heat which is produced by        the at least one first LED during operation can be dissipated        from the first base body to the first heat sink.

Normally, halogen lamps or halogen reflector lamps are used to producelight in airfield lighting devices. These have a high operatingtemperature of several hundred ° C., and therefore a high thermal powerloss. In comparison to halogen lamps, LEDs may have a considerably lowerthermal power loss and at the same time a longer life, and may be morereliable. However, in order to achieve a long life for an LED such asthe at least one first LED in the airfield lighting device describedhere, it is necessary for the temperature in layers of the LED whichproduce the light to be kept permanently below a critical limit in orderto ensure that no premature degradation effects occur in the LED, whichcan shorten the life. By way of example, the boundary layer temperaturein an LED must be kept below a temperature of 125° C., and preferablybelow a temperature of 90° C., for a continuous operation. While knownheat sinks of the size of halogen reflector lamps are too small forefficient cooling and the dissipation of the heat produced by the atleast one LED during operation via metal plates or by means of freeconvection to the housing is not efficient enough, the first thermallyconductive tube allows efficient heat conduction from the first basebody to the first heat sink of the heat which is produced by the atleast one first LED during operation.

In this case, the at least one first LED can be arranged on the firstbase body such that the at least one first LED makes thermal contactwith the first base body. The heat produced during operation of the atleast one first LED can in this case be transferred to the first basebody via a contact surface with said first base body. The thermalcontact between the first base body and the first thermally conductivetube furthermore allows the heat to be transferred to the firstthermally conductive tube. In this case, the first thermally conductivetube may have a first subarea and a second subarea, such that heat canbe transported from the first subarea to the second subarea by means ofthe heat transmission medium. The first subarea and the second subareaare particularly preferably mutually opposite sides or ends of thethermally conductive tube. In this case, the first subarea may makethermal contact with the first base body, while the second subarea canmake thermal contact with the first heat sink. The first thermallyconductive tube can furthermore have an internal volume which iscompletely surrounded by an outer wall and in which the heattransmission medium is located.

The first subarea can preferably be arranged at a first end of thethermally conductive tube. The first thermally conductive tube may, inparticular, be suitable for emitting heat in the first subarea, that isto say thermal energy, from the at least one first LED to the heattransmission medium. In this case, the heat transmission medium in thefirst subarea can change at least partially from a first state to asecond state, wherein the first state and the second state may, forexample, be different aggregate states. In particular, the first statemay comprise a solid and/or a liquid phase, and the second state maycomprise a vapor phase. In particular, this can mean that the heattransmission medium can vaporize or sublimate in the first subarea byabsorption of heat from the heat source. In this case, the heattransmission medium may have a first vapor pressure in the firstsubarea. Alternatively or additionally, the first state may likewisecomprise a vapor phase, in which case the density of the second statecan then preferably be lower than the density of the vapor phase in thefirst state.

At least a portion of the heat transmission medium, which is in thesecond state in the first subarea after absorption of heat, can then bemoved to the second subarea, which is preferably arranged at a secondend of the thermally conductive tube, for example by convection forces.In the second subarea, the heat transmission medium can change back fromthe second state to the first state again, by heat emission, that is tosay for example it can condense or resublimate. In particular, it mayalso be possible for the heat transmission medium in the second subareato have a second vapor pressure, which is lower than the first vaporpressure. The heat released by the transfer of the heat transmissionmedium can then be emitted from the second subarea to the environment,in particular to the first heat sink.

In particular, the functional principle described above can result inthe first subarea being at a higher temperature than the second subarea.

The heat transmission medium in the first state in the second subareacan then, for example, be transported back to the first subarea by theaction of one or more forces, for example by the force of gravity and/orby capillary forces. In particular, network structures, sinteredstructures, grooves or channels or combinations thereof, which arearranged in the internal volume or surrounding the internal volume inthe thermally conductive tube, may be suitable for transporting the heattransmission medium from the second subarea to the first subarea bycapillary forces.

By way of example, the first thermally conductive tube which can conductheat by means of the heat transmission medium according to theabovementioned principle may comprise or be a thermosyphon or,particularly preferably, a so-called heat pipe. A thermally conductivetube such as this operating on the abovementioned principle may beadvantageous for passing heat efficiently from its first subarea to itssecond subarea economically, without consumption of additional energy.In particular, the airfield lighting device may have a heat pipe as thefirst thermally conductive tube. In this case, for efficient heatconduction by means of the heat transmission medium, this airfieldlighting device may have an installation orientation, which is requiredfor operation, in relation to the force of gravity direction, and/or inrelation to the direction in which the airfield extends. In particular,this can mean that the first thermally conductive tube, when theairfield lighting device is installed in this way, leads horizontallyfrom the first base body to the first heat sink.

The first thermally conductive tube may have an elongated shape, in theform of a rod. In particular, the first thermally conductive tube may inthis case have a circular cross section at right angles to alongitudinal axis. The first subarea and the second subarea of the firstthermally conductive tube may in this case advantageously be formed bythe end areas of the shape in the form of a rod. Alternatively oradditionally, the first thermally conductive tube may also have anelliptical cross section or a polygonal cross section with n sides,where n may be an integer greater than or equal to 3. Furthermore, thefirst thermally conductive tube may also have a plurality of internalvolumes, which are formed separately from one another, with the heattransmission medium. It may also be possible for the first thermallyconductive tube to have a plurality of thermally conductive tubes whichcan make thermal contact with the first base body and the first heatsink independently of one another, or else may be integrated in a commoncomponent, for example as two thermally conductive tubes which are inthe form of rods and are connected along their length. Furthermore, thefirst thermally conductive tube may have an elongated shape or else ashape which is bent at least in subareas.

The fact that the first thermally conductive tube is thermally coupledto the first base body and to the first heat sink can therefore mean, inparticular, that the first subarea of the first thermally conductivetube makes thermal contact with the first base body and therefore alsowith the at least one first LED which is arranged on the first basebody, and the second subarea of the first thermally conductive tubemakes contact with the first heat sink.

In this case, a thermal contact such as this or a thermal coupling canbe provided by a mechanical contact, for example via contact surfaces orcontact areas in each case on the first thermally conductive tube, thefirst base body and the first heat sink. In particular, the first basebody and/or the first heat sink may in this case have, for example, ahole, groove or opening as contact surfaces, into which the firstthermally conductive tube can partially project, and/or in which thefirst thermally conductive tube can partially run. In this case,furthermore, the thermal coupling between contact surfaces or contactareas can furthermore be improved by a connecting medium which conductsheat, for example a thermally conductive paste, which is applied tocontact surfaces or contact areas, and/or a soldered joint with asolder.

The first thermally conductive tube can in each case be connected to thefirst base body and/or to the first heat sink by means of a detachableform of attachment. In this case, a detachable form of attachment may,in particular, be a mechanical type of attachment such as screws, plugs,flanges, clamps or a combination thereof. Furthermore, the firstthermally conductive tube may be connected to the first base body and/orto the first heat sink by means of a form of attachment which can bedetached only with difficulty after attachment or which is notdetachable in normal conditions, such as soldering, welding, adhesivebonding or a combination thereof. The first thermally conductive tubecan also be connected to the first base body and/or to the first heatsink by means of a combination of two or more types of attachmentmentioned above, that is to say a combination of plugs, clamps, flanges,soldering, welding, adhesive bonding and/or screws.

The heat transmission medium may preferably have water. Alternatively oradditionally, the heat transmission medium may have ethane, propane,butane, pentane, propene, methylamine, ammonium, methanol, ethanol,methylbenzene, acetone and/or carbon dioxide, or a mixture orcombination thereof. By way of example, the heat transmission medium mayhave water and an antifreeze agent, for example an alcohol, as a resultof which the first thermally conductive tube may also keep the heattransmission medium at least partially in the liquid phase below thefreezing point of water.

Furthermore, there may be a lower pressure than the ambient air pressurein the internal volume, in comparison to the air pressure in thesurrounding area outside the internal volume. Alternatively, there mayalso be a higher pressure than the ambient air pressure in the internalvolume. A desired temperature range, within which the first thermallyconductive tube can operate efficiently, can be set by setting thepressure in the internal volume, together with the choice of the heattransmission medium and the choice of the dimensions of the firstthermally conductive tube, such as length, shape and diameter. Inparticular, official regulations for airfield lighting devices mayactually require reliable and continuous operation in a temperaturerange from −55° C. to +55° C.

Furthermore, the first thermally conductive tube may have a materialwith high thermal conductivity, in particular a metal such as copper oraluminum. In particular, the first base body may also have a material ofhigh thermal conductivity, in particular a metal such as copper oraluminum. Furthermore, the first base body may, for example, also have ametal core plate such as an aluminum core plate or may be such a coreplate. In this case, the first base body may have mechanical andelectrical contacts and contact surfaces such as a mounting surface orelectrical conductor tracks, by means of which the at least one firstLED can be mechanically and electrically connected.

Furthermore, the first heat sink may form at least a part of the housingin which the at least one first LED is arranged on the first base body.This can mean that the first heat sink may, for example, form a part ofa housing wall which bounds the at least one first LED on the first basebody from the area surrounding the airfield lighting device. This makesit possible to ensure efficient dissipation of the heat from the atleast one LED via the first base body, the first thermally conductivetube and the first heat sink to the area surrounding the airfieldlighting device.

The first heat sink may be formed and arranged circumferentially aroundthe first base body. A first heat sink such as this can therefore bearranged in a space-saving manner around the first base body, such thata compact airfield lighting device can be made possible. In particular,the first heat sink may in this case surround the first base body, thusallowing uniform, symmetrical heat dissipation from the first heat sinkto the area surrounding the airfield lighting device. By way of example,the first heat sink may be cylindrical with a circular, elliptical,triangular or polygonal cross section, or a combination thereof.

Furthermore, the first heat sink may have a material with a high thermalconductivity such as a metal, for example copper or aluminum. Inparticular, it may be advantageous for the first heat sink to have ahigh surface-area to volume ratio. In this context, the heat sink canpreferably have grooves, cooling ribs, laminates and/or fins. By way ofexample, this allows heat to be emitted over a large area andefficiently to the surrounding area. For example, the first heat sinkmay have a plurality of grooves, cooling ribs, laminates and/or fins,circumferentially around the first base body, on an outer surface facingaway from the first base body. Particularly if the first heat sink formsat least a part of a wall of the housing, the grooves, cooling ribs,laminates and/or fins may also be arranged on the outside of thehousing, that is to say on the outside of the housing wall.

In addition to the first heat sink on the airfield lighting device, thefirst base body may itself have a second heat sink. In this case, thefirst base body may also be in the form of a second heat sink, on whichthe at least one first LED is arranged. The second heat sink canincrease the dissipation of heat from the at least one first LED, inaddition to the heat dissipation through the first thermally conductivetube and the first heat sink. Since the first base body and thereforealso the second heat sink are arranged in the housing of the airfieldlighting device, heat can be emitted into the interior of the housingfrom the at least one first LED via the second heat sink. This may beadvantageous, for example, when the ambient temperature in which theairfield lighting device is arranged is so low that the heattransmission medium in the first thermally conductive tube when the atleast one first LED is not in operation is entirely frozen, or is frozenat least to such a major extent that, immediately after starting up, theat least one first LED, the heat transmission medium cannot circulate orcannot circulate adequately in the thermally conductive tube in order toallow the heat produced by the at least one first LED to be efficientlydissipated to the first heat sink. The second heat sink then makes itpossible to dissipate the heat produced by the at least one first LEDinto the interior of the housing, and thus to redistribute it such thatthe temperature in the housing and therefore also in the first thermallyconductive tube can be raised above the ambient temperature, thusallowing the heat transmission medium to circulate adequately in thefirst thermally conductive tube again. Alternatively or additionally, aheating element for heating the first thermally conductive tube can bearranged in the housing, in order to heat the first thermally conductivetube to an operating temperature which is required for heat dissipation.For example, the operating temperature may be given by a meltingtemperature or boiling temperature of the heat transmission medium.

In the case of the airfield lighting device described here, it may bepossible that the electrical power of the at least one LED need not berestricted as a result of a need to prevent the risk of overheating ofthe LED in the housing. In fact, it may be possible for the at least onefirst LED to have an electrical power of more than 20 watts.Particularly in the case of a high-power LED such as this, the heatdissipation described here by means of the first thermally conductivetube and the first heat sink may make it possible to achieve a long lifefor the airfield lighting device.

Furthermore, the at least one first LED may also comprise or be an LEDarray, which means an arrangement of a plurality of LEDs of the same ordifferent types, on the first base body. The at least one LED or theLEDs in the LED array can preferably emit light in a visible wavelengthrange, and can therefore give the viewer the impression, for example, ofa single-color, mixed-color or white-color light. Features of LEDs andLED arrays such as these are known to those skilled in the art, and willnot be discussed any further here.

In addition to the at least one first LED and the first base body, theairfield lighting device may have at least one second LED on a secondbase body. Furthermore, the airfield lighting device may have a secondthermally conductive tube, which is thermally coupled to the second basebody and to the first heat sink and which has a heat transmission mediumwhich can circulate in the second thermally conductive tube duringoperation of the at least one second LED. This allows the heat producedby the at least one second LED to be dissipated from the second basebody to the first heat sink.

In this case, the second base body may have features such as thosedescribed in conjunction with the first base body. The second thermallyconductive tube may have features such as those described in conjunctionwith the first thermally conductive tube. The at least one second LEDmay have features such as those described in conjunction with the atleast one first LED.

In particular, the first base body and the second base body may bearranged in the housing such the at least one first LED and the at leastone second LED can emit light in the same directions or in mutuallydifferent directions during operation.

Further advantages as well as advantageous embodiments and developmentsof the airfield lighting device will become evident from the embodimentsdescribed in the following text, in conjunction with FIGS. 1 to 2B, inwhich:

FIG. 1 shows a schematic illustration of an airfield lighting deviceaccording to one exemplary embodiment, and

FIGS. 2A and B show schematic illustrations of an airfield lightingdevice according to a further exemplary embodiment.

In the exemplary embodiments and figures, identical components orcomponents having the same effect may in each case be provided with thesame reference symbols. The illustrated elements and the relationshipsbetween the ratios of their sizes should in principle not be consideredas being true to scale, and in fact individual elements such as layers,parts, components and areas may be illustrated with exaggeratedly thickor large dimensions in order to illustrate them better and/or for betterunderstanding.

FIG. 1 shows an exemplary embodiment for an airfield lighting device100. This is arranged in a depression 97 on an airfield 98, that is tosay for example a runway or a taxiway. A plurality of such airfieldlighting devices 100 recessed in the ground may, for example, identifythe edge boundaries or the center line of the airfield 98.

The airfield lighting device 100 has at least one first LED 1, which canemit light in the direction identified by the arrow 99. The at least onefirst LED may in this case emit light with an officially specified colorand with an officially specified emission characteristic, depending onthe form of the airfield 98. For example, airfield lighting devices atthe edge of taxiways typically give a blue light impression, and thoseat the edge of the runways give a white light impression. Airfieldlighting devices for center-line mapping, for example, may also give awhite-colored light impression, a white and red-colored light impressionor a red-colored light impression, depending on the position on arunway. In order to comply with the officially required brightness, theat least one first LED 1 has a power of more than 20 W. As analternative to this, the at least one first LED 1 may also be in theform of an LED array, that is to say comprising a plurality of LEDS,which together have the required emission characteristic and brightness.

The at least one first LED 1 is arranged on a first base body 2, whichis used as a mechanical mount and has electrical supply lines for theelectrical connection of the at least one first LED 1. In theillustrated exemplary embodiment, the first base body 2 is in the formof an aluminum core plate, which makes thermal contact with the at leastone first LED 1.

A first thermally conductive tube 3 with a heat transmission medium 31in an internal volume of the first thermally conductive tube 3 makesthermal contact with the first base body 2 and with a first heat sink 4.In this case, the thermally conductive tube 3 is designed such that theheat transmission medium 31 can circulate in its internal volume and candissipate to the first heat sink 4 heat which is created duringoperation of the at least one first LED 1.

Furthermore, the airfield lighting device 100 has a housing 5 which, inthe illustrated exemplary embodiment, has a cover 51 and a lower part52, which enclose a housing internal volume 50. The at least one firstLED 1 is arranged on the first base body 2, and the first thermallyconductive tube 3 is arranged within the housing 5. The first heat sink4 is designed such that heat which is dissipated from the at least onefirst LED 1 by means of the first thermally conductive tube 3 to thefirst heat sink 4 can be emitted to the surrounding area, that is to sayin the illustrated exemplary embodiment to the depression 97 in theairfield 98. For this purpose, the first heat sink 4 makes thermalcontact with the wall of the lower part 52 of the housing 5.

Additionally, a heating element (not shown) can also be fitted in thehousing interior volume 50, which is suitable for heating the firstthermally conductive tube 3 to an operating temperature which isrequired for heat dissipation, as described in the general part above.

Further optical, electrical and mechanical components such as windows inthe cover 51, lenses, electrical lines and components or mechanicalholding apparatuses for the individual components described here are notshown, for the sake of clarity. However, these can additionally bearranged in the housing internal volume 50. Furthermore, for example,electrical supply lines and/or components such as transistors can bearranged in the depression 97 outside the housing 50, and can be passedinto the airfield lighting device 100 via suitable plug connectionsand/or bushings (not shown).

As an alternative to the airfield lighting device 100 recessed in theground in the exemplary embodiment as shown here, the airfield lightingdevice 100 may, for example, also be arranged on a supporting device,such as a post, above the airfield 98.

FIGS. 2A and 2B show schematic three-dimensional illustrations of afurther exemplary embodiment 200 for an airfield lighting device,wherein FIG. 2A shows only the lower face 52 of the housing 5, incomparison to the airfield lighting device 100 shown in FIG. 1, whilethis illustration omits the cover 51, for sake of clarity. In comparisonto FIG. 2A and in order to assist understanding, FIG. 2B shows only thecomponents which are arranged within the housing 5 in FIG. 2A. Thefollowing description relates equally to both FIGS. 2A and 2B.

The airfield lighting device 200 has a heat sink 4 which is part of thelower face 52 of the housing. The heat sink 4 has a cylindrical shapeand in this case surrounds a housing internal volume 50, in which aplurality of first LEDs 1 are arranged on a first base body 2, and aplurality of second LEDs 6 are arranged on a second base body 7. Theplurality of first LEDs 1 and the plurality of second LEDs 6, of whichin each case two LEDS are shown purely by way of example, in each casewith an optical element for beamforming, are in this case arranged suchthat they emit light independently in mutually different directions.

The first base body 2 and the second base body 7 are each in the form ofsecond heat sinks with cooling laminates 21 and 71, respectively, bywhich means the heat created by the respective LEDs 1 and LEDs 6 duringoperation can be at least partially dissipated into the housing internalvolume 50, as described in the general part above.

A first thermally conductive tube 3 is thermally connected to the firstbase body 2, with one end of the first thermally conductive tube 3 beingplugged into an opening in the first base body, and with the firstthermally conductive tube 3 running away from the first base body 2 in acurved shape toward the first heat sink 4. For this purpose, the firstthermally conductive tube 3 has a shape similar to a spiral, which ismatched to the shape of the inside of the first heat sink 4 facing thefirst and second base bodies 2, 7. In this case, the first thermallyconductive tube 3 is arranged circumferentially around the first basebody 2, along an inner surface of the first heat sink 4. The first heatsink 4 additionally has a groove, in which the first thermallyconductive tube 3 is arranged along approximately half the internalcircumference of the first heat sink 4. This results in a large-areathermal contact between the first thermally conductive tube 3 and thefirst heat sink 4.

A second thermally conductive tube 8 is thermally connected to thesecond base body 7, with one end of the second thermally conductive tube8 being plugged into an opening in the second base body 7, and with thesecond thermally conductive tube 8 having a shape similar to spiral, inthe same way as the first thermally conductive tube 3, and likewisebeing arranged in a groove in the first heat sink 4. The first thermallyconductive tube 3 therefore runs along the inner surface of the firstheat sink 4 toward the second base body 7, while the second thermallyconductive tube 8 runs along the inner surface of the first heat sink 4toward the first base body 2. As can be seen in particular from FIG. 2B,this allows an extremely compact arrangement of the first and secondbase bodies 2, 7 and of the first and second thermally conductive tubes3, 8 in the housing internal volume 50, while at the same time in eachcase allowing a large-area thermal contact between the thermallyconductive tubes 3, 8 and the first heat sink 4.

In the illustrated exemplary embodiment as described further above, thethermally conductive tubes 3, 8 are heat pipes, which are arranged atthe level of the LEDs 1, 6, or alternatively underneath them. When theairfield lighting device 200 is in the installed state, for example asshown in FIG. 1, the thermally conductive tubes 3, 8 run along the firstheat sink 4 in the horizontal direction. In this case, “horizontal” isdefined with respect to the force of gravity direction when the airfieldlighting device 200 is in an installed state. This means that theinstallation orientation of the airfield lighting device 200 in theillustrated exemplary embodiment is such that the cylinder axis of thefirst heat sink 4 is parallel to the force of gravity direction, when inthe installed state.

The heat sink has a plurality of cooling ribs 41 which runcircumferentially around the base bodies 2, 7 on the outer surfacefacing away from the first and second base bodies 2, 7, that is to sayon the outside of the housing. This allows large-area thermal couplingof the first heat sink 4 and therefore of the housing of the airfieldlighting device 200 to the surrounding area, for example in a depressionin an airfield as shown in FIG. 1. This makes it possible to ensureeffective heat dissipation from the first heat sink 4 to the surroundingarea. Alternatively or in addition to the illustrated vertical coolingribs, the first heat sink 4 may also have cooling ribs or coolinglaminates which are radially circumferential horizontally or inclinedaround the housing internal volume 50.

The description based on the exemplary embodiments, does not restrictthe invention to these exemplary embodiments. In fact, the inventioncovers every novel feature and every combination of features, inparticular including every combination of features in the patent claims,even if this feature or this combination is not itself explicitlymentioned in the patent claims or exemplary embodiments.

1. An airfield lighting device, comprising: at least one firstlight-emitting diode on a first base body; a first thermally conductivetube with a heat transmission medium; a first heat sink; and a housing,in which the first base body and the first thermally conductive tube arearranged, wherein the first thermally conductive tube is thermallycoupled to the first base body and to the first heat sink, and whereinthe heat transmission medium can circulate in the first thermallyconductive tube, such that heat which is produced by the at least onefirst LED during operation can be dissipated from the first base body tothe first heat sink.
 2. The airfield lighting device as claimed in claim1, wherein the first heat sink is at least part of a housing in whichthe first base body with the at least one first LED is arranged.
 3. Theairfield lighting device as claimed in claim 1, wherein the first heatsink is arranged circumferentially around the first base body.
 4. Theairfield lighting device as claimed in claim 1, wherein the first heatsink surrounds the first base body.
 5. The airfield lighting device asclaimed in claim 1, wherein the first heat sink cylindrically surroundsthe first base body.
 6. The airfield lighting device as claimed in claim5, wherein the first heat sink has a plurality of cooling ribs,circumferentially around the first base body, on an outer surface facingaway from the first base body.
 7. The airfield lighting device asclaimed in claim 1, wherein the first base body comprises a second heatsink.
 8. The airfield lighting device as claimed in claim 1, wherein thefirst thermally conductive tube is plugged into an opening in the firstbase body.
 9. The airfield lighting device as claimed in claim 1,wherein the airfield lighting device has an installation orientation,which is required for operation, in relation to the force of gravitydirection, and wherein the first thermally conductive tube, when theairfield lighting device is installed in this way, leads horizontallyfrom the first base body to the first heat sink.
 10. The airfieldlighting device as claimed in claim 1, wherein the first thermallyconductive tube leads away from the first base body in a curved shape tothe first heat sink.
 11. The airfield lighting device as claimed inclaim 1, wherein the first thermally conductive tube is arrangedcircumferentially around the first base body, along an inner surface ofthe first heat sink.
 12. The airfield lighting device as claimed inclaim 1, wherein the at least one first LED has an electrical power ofmore than 20 watts.
 13. The airfield lighting device as claimed in claim1, further comprising: at least one second light-emitting diode on asecond base body; and a second thermally conductive tube with a heattransmission medium, wherein the second thermally conductive tube isthermally coupled to the second base body and to the first heat sink,and wherein the second heat transmission medium can circulate in thesecond thermally conductive tube during operation of the at least onesecond LED, such that heat which is produced by the at least one secondLED during operation can be dissipated from the second base body to thefirst heat sink.
 14. The airfield lighting device as claimed in claim13, wherein the at least one first LED and the at least one second LEDemit light in mutually different directions during operation.
 15. Theairfield lighting device as claimed in claim 13, wherein the first heatsink cylindrically surrounds the first and second base bodies.
 16. Theairfield lighting device as claimed in claim 13, wherein the firstthermally conductive tube runs in a curved shape along an inner surface,which faces the first and the second base bodies, of the first heat sinkto the second base body, and wherein the second thermally conductivetube runs in a curved shape along the inner face of the first heat sinkto the first base body.
 17. The airfield lighting device as claimed inclaim 1, further comprising a heating element for heating the firstthermally conductive tube to an operating temperature which is requiredfor heat dissipation.